Okay managed to fix this problem at last. So sorry for reviving a dead post and this double post.
As mentioned in the "user manual"
1.1.1 Location of Client Data
You must define the "Client Data" repository with the directory where you had expanded your data.saf.
All the icons and textures, but also data files when cross-edition is performed, will then be read from this repository.
Simply click on the text field to open the "Choose Folder" dialog and then choose the directory.
The choice of this directory shall be performed before first use, it can then be made as often as necessary.
This WILL fix the problem with the somo2 error. Just make sure you specify the file where you extracted the files you want to edit to.. not the file containing your game.exe like i had.
So anyone else having this problem, save Caster from the repeated questions and just do that to fix, pretty simple really..